The present invention is directed to a method for manufacturing an optical cable, wherein a supporting member is produced with an extruder and is thereby provided with chambers or grooves that helically proceed in alternate directions with a defined spacing between reversing points and whereby light waveguides are subsequently placed in these chambers or grooves at an insertion point.
German OS No. 29 22 986 discloses an arrangement wherein helically proceeding chambers or grooves are provided on a supporting member and can have a changing running direction so that they have a defined spacing between reversing points, similar to the known SZ-stranding. In detail, one thereby proceeds so that a fixed extruder unit is provided that is followed by a twisting unit at a definite distance following an intermediate cooling station. This twisting unit has the job of exerting a torsion on the finished supporting member that is already provided with the chambers and exerting this torsion so that the effect of the torsion extends backward up to the extruder head of the extruder unit and causes an oscillating motion there of the tension element passing through the extruder head. The chambers, which helically proceed in different directions in alteration, are produced in this fashion. The twisting unit is followed by an insertion unit that works with two oscillating insertion disks for the light waveguides. In addition to the outlay for the insertion disks, a disadvantage of this arrangement is that a control and guide means is required in order to guarantee the synchronization of the insertion disks. The cause of this lies in the fact that the rotational angle of the central element becomes smaller and smaller proceeding from the rotational unit with increasing distance, so that it is not possible to couple chamber manufacture and element insertion.
European application Ser. No. EP-A1 0 171 841 discloses a manufacturing method for a chambered cable, wherein the twisting of the tensile element is undertaken before the extruder so that the torsion motion forced in this way is still also noticeable at the actual extruder head. Since the twisting occurs in a periodically changing direction, helical chambers respectively proceed in different directions in the alteration that occurs at the output of the extruder head. Here, too, the element turning decreases from the turning means up to the insertion mechanism so that the latter must be independently controlled. The insertion event is carried out so that a rotating insertion mechanism is provided and the output of this mechanism comprising guide tubes for the introduction of the light waveguides into the chamber of the supporting member. Here, too, the rotation of the insertion mechanism must follow the course of the chambers, for example corresponding controls and guide devices must be provided.